Many of the commercial buildings built in the 1970's and thereafter were constructed to reduce energy consumption because of the high cost of energy. As a result, such buildings did not have windows that opened and closed, and had to rely on indoor air that was filtered and recirculated through heating, ventilation, and air conditioning systems. The extensive ducts used in these systems would not only become dirty from entrained impurities, but the warm, moist environments defined by the interior of these ducts provided optimum conditions for the growth of debris, particulates, asbestos fibers, pathogens, fungi, and the like. These pathogens and fungi become entrained in the circulating air and are subsequently inhaled by tenants and persons in the buildings.
Public awareness of these problems has resulted in building owners and landlords developing policies that require periodic cleaning of the air handling systems. Some commercial cleaning apparatuses are extremely bulky and heavy in order to clean air handling ducts located at points remote from the blower systems. For example, while commercial cleaning equipment located on the ground floor may be effective in cleaning the air ducts in the lower floors of a building, it is difficult for this equipment to effectively clean the air ducts in the upper floors because of the great length of the suction hoses required to reach these higher floors. Further, this kind of commercial cleaning equipment requires extremely large blowers in order to generate the vacuum needed to clean the remotely located air ducts. Some present commercial cleaning equipment is much too large to be transported by elevators to each floor of the building, and the cleaning components are usually located at points remote from the ducts to be cleaned. Other portable-type equipment simply does not have the means for producing the necessary air volume to effectively clean duct systems of commercial heating, ventilating, and air conditioning systems of commercial buildings and the like.